I just downloaded a copy of Dash Command to run via my iPhone and think I have most of the "advanced" vehicle settings in place. However, still have a couple of missing parameters for my '05 R53 automatic and am hoping someone already has it figured out.

My Dashcommand iOS vehicle settings thus far are:

Engine displacement: 1598cc
Fuel type: Gasoline
Fuel tank capacity: 13.2 gal
Brake Specific Fuel Consumption: ???*
Tire size specification: 195/55R16


Final drive ratios:

• Axle ratio: 3.683*
• 1st gear: 4.044
• 2nd gear: 2.371
• 3rd gear: 1.556
• 4th gear: 1.159
• 5th gear: 0.852
• 6th gear: 0.672

Curb weight: 2723 lb
Additional weight: variable
Drag coefficients: 0.36
Frontal area: 1.98 square meters
Maximum engine speed: 6500 rpm*
Minimum engine speed: 700 rpm*

Most of the info I was able to obtain via this *very* handy little chart of tech specs for '05 MINIs from Motoringfile:

http://www.motoringfile.com/files/MINI_2005_specs.pdf

* = parameters I'm unsure about

Questions still remaining/pending confirmation:

Brake specific fuel consumption: Palmer says "Try .45 for naturally aspirated gasoline engines, .55 for forced induction gasoline engines, and .35 for turbo diesel engines." It sounds like the R56 folks are about on target at .50. Figure about the same for the R53?

Volumetric efficiency: Palmer says "A value between 60 and 85 is an appropriate starting point".

Max engine speed: 6500 rpm?

Min engine speed: 700 rpm?

Shift point: Palmer says "Set to most economical shift rpm." Not sure how this applies to an automatic transmission. If left to it's own devices, it seems to upshift around 3000-3500 rpm.

Thanks in advance to anyone who is able to help out!

 

Tim,

Sorry to raise this necro thread, but I just got DashCommand for my R55 S and I was curious if you found answers to your questions.

 

Sorry for the delayed response..... No, no answers as yet.

 

BSFC is HP ÷ fuel consumption. http://en.wikipedia.org/wiki/Brake_specific_fuel_consumption
Has the calculations on the page or check Google.

Vol efficiency is hard to find. For some reason it is super secret squirrel business.

Good luck!

James

 

FYI. Those are engine performance scalars used in thermodynamics.

From Wikipedia:

Brake specific fuel consumption (BSFC) is a measure of the fuel efficiency of any prime mover that burns fuel and produces rotational, or shaft, power. It is typically used for comparing the efficiency of internal combustion engines with a shaft output.

It is the rate of fuel consumption divided by the power produced. It may also be thought of as power-specific fuel consumption, for this reason. BSFC allows the fuel efficiency of different engines to be directly compared.

To calculate BSFC, use the formula

BSFC = r/P
where:

r is the fuel consumption rate in grams per second (g/s)
P is the power produced in watts where P = tau * omega
omega = the engine speed in radians per second (rad/s)
tau = the engine torque in newton meters (N·m)

It takes some unit conversions, but the values needed should be available.

 

The volumetric efficiency is a little harder. It would be 100% (1.00) if the airflow under dynamic conditions was equal to the calculated air volume displaced by the Pistons. Greater than 1.0 is possible for forced induction. Variable valve timing and true tuned (on a flow bench) exhaust systems also increase this value.

The number in the denominator is just for unit conversion.

VE (at 100% AIRFLOW) (scfm) = (DISPLACEMENT (ci) x RPM) / 3456

Assuming you know the displacement, If you have cfm flow data as a function of rpm, you can calculate your value using the equation above.

 

Thanks!

 

There's a graph of VE about 2/3 down this page.


https://www.northamericanmotoring.com/forums/drivetrain-cooper-s/73771-m62-sc-on-the-mini-is-reality-15.html